Oh, I have one more 
Now that the MTR-5B box is completed, I had the courage to take a apart my MTR-3B-based predecessor and complete the smaller version, which I call “TinySOTA” (will also be on GitHub).
It is a Mountain Topper 3-Bander PCB plus
- 2 cells of 1000 mAh Lipo batteries
- the DC-DC step-up converter with input and output filters for getting 9 and 12 V out of the 2S batteries (GitHub - mfhepp/gobox-power: A 6-9-12V DC-DC boost converter for QRP rigs from 4 NiMH cells (or 2S LiPo with minor mods), e.g. Mountain Topper MTR-3B and MTR-5B. with a 6.2V zener diode and 470 R instead of 220 R for the LEDs),
- the TinySWR indicator,
- a volume control,
- the USB-powered 2S balanced Lipo charger from Micro USB 2S Balance Charger, and
- a Palm Pico Single paddle.
The total weight is 315 g including battery, charger, paddle and earphone. The box is watertight and should allow for 2 - 3 hrs of SOTA activity.
Attached, please find a few pictures. The front panel will eventually also be made in aluminium.
This one is a much trickier project than the MTR5B GoBox, because you have to do quite a few mods on the MTR PCB. For instance, reusing the power switch requires unsoldering the Q5 transistor which serves as a polarity protection. Also, space is so tight that I had to shorten the wires of the four push-button switches, etc.
73 de Martin, DK3IT
